Although their potential is far from being fully realized, cell surface receptors have proven to be very effective therapeutic targets in a variety of clinical settings. Effective biologicals and small molecules targeted to receptors appear to act by a variety of mechanisms ranging from receptor antagonists to induction of apoptosis, to targeting of cells for destruction by their innate immune system. To reach the full potential of this approach a more complete understanding of cell surface receptor structure-function relationships and signaling will be necessary. The progress toward this goal can be attained most rapidly when interactions among clinicians and scientists are maximized by focused conferences. We apply herein for NIH support of the 2005 FASEB conference on "Immunoreceptors" to be held in Tucson, Arizona July 23-28, 2005. The conference has evolved from a series of successful conferences held bi-annually since the early 1980's that originally focused on the question of immunoglobulin constant region (Fc) receptor function. In recent iterations, the scope of the meeting has broadened to consider function of other immune system receptors that contain lg-folds. The conference will bring together experts who, although they come from different disciplines, share interests in the family receptors including: molecular structure and how it informs function, role of these receptors in inflammation, signal transduction and exploitation in the clinic. Goals for the conference include fertilization across these disciplines and involvement of young, female and minority scientists in these research areas. Thus among the invited 33 speakers there will be 9 women and an additional 8 presentations will be solicited from young scientists who submit abstracts. Major themes will be 1) molecular structure-function, 2) intermolecular interactions and proximal signaling, 3) membrane domains, 4) immunological synapses, 5) inhibitory receptors and feedback loops and 6) clinical applications in inflammation, autoimmunity and cancer. This conference is structured to provide an optimal opportunity for cross-discipline interaction as well as a balanced treatise on the most contemporary and contentious problems in our field. Hopefully, it will nurture translational studies to develop therapeutic compounds targeted to cell surface molecules.